A086168 a(n) = sum of the first n upper twin primes.

5, 12, 25, 44, 75, 118, 179, 252, 355, 464, 603, 754, 935, 1128, 1327, 1556, 1797, 2068, 2351, 2664, 3013, 3434, 3867, 4330, 4853, 5424, 6025, 6644, 7287, 7948, 8759, 9582, 10411, 11270, 12153, 13174, 14207, 15258, 16321, 17414, 18567

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

For n = 4 we have twin prime pairs (3,5) (5,7) (11,13) (17,19) and 5 + 7 + 13 + 19 = 44.

Mathematica

lst={}; s=0; Do[p=Prime[n]; If[PrimeQ[p-2], s+=p; AppendTo[lst, s]], {n, 6!}]; lst (* Vladimir Joseph Stephan Orlovsky, Sep 30 2008 *)
Accumulate[Transpose[Select[Partition[Prime[Range[200]], 2, 1], Last[#]-First[#]==2&]][[2]]]  (* Harvey P. Dale, Feb 08 2011 *)

Prog

(PARI) addnexttwin(n)= { s=0; for(x=1, n, if(prime(x+1)-prime(x)==2, s=s+prime(x+1); print1(s", ")) ) }

Crossrefs

Cf. A006512, A086167.

Sequence in context: A212058 A303854 A331714 * A301748 A108201 A289586

Adjacent sequences: A086165 A086166 A086167 * A086169 A086170 A086171

Keyword

nonn

Author

Cino Hilliard, Aug 25 2003

Status

approved